Questions: Observing and Describing Matter

Question 1

A student describes a rock as 'pretty cool.' A scientist describes the same rock as 'a rough, gray, opaque solid about 5 cm wide with dark speckles.' Which description is more useful for science?

• A. The student's — it is shorter and easier to understand
• B. The scientist's — it uses specific property words that help anyone identify and compare the rock
• C. Both are equally useful — they describe the same rock
• D. Neither — you need a microscope to truly describe a rock

Answer: (B)

The scientist's description uses specific, measurable property words — rough texture, gray color, opaque, 5 cm size, and dark speckles. Anyone reading this could identify the rock or compare it to another. 'Pretty cool' tells you nothing about the rock's actual properties.

Question 2

The primary way to observe matter is by looking at it.

• T. True
• F. False

Answer: False

False. You can observe matter with all of your senses. Touch tells you about texture, hardness, and temperature. Smell can identify substances. Hearing can help too — tapping a metal bowl sounds different from tapping a plastic one. Sight is just one of several tools for observation.

Question 3

List three properties you could use to describe a wooden pencil.

Model answer: Possible answers include: yellow color, cylindrical shape, lightweight, smooth texture (painted surface), solid state, about 19 cm long, opaque, made of wood with a graphite center, has a rubber eraser on one end.

A good description uses multiple properties. Color, shape, size, texture, weight, and material are all valid properties you can observe. The more specific your description, the easier it is for someone else to know exactly what you are talking about.